Z.A. Ansari¹ , Shahin Badesab¹ , R. Singh¹ , Hiroshi Kitazato²

1 National Institute of Oceanography, Dona Paula Goa 403004, India
2 Japan Agency for Marine-Earth Science and Technology, Natsushima 2-15, Yokosuka, Kanagawa 237-0061, Japan
Author    Correspondence author
International Journal of Marine Science, 2017, Vol. 7, No. 7   doi: 10.5376/ijms.2017.07.0007
Received: 03 Jan., 2017    Accepted: 16 Feb., 2017    Published: 06 Mar., 2017

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Ansari Z.A., Badesab S., Singh R., and Kitazato H., 2017, Meiofaunal distribution across the oxygen minimum zone of continental margin, north east Arabian Sea, International Journal of Marine Science, 7(7): 59-66 (doi: 10.5376/ijms.2017.07.0007)

A quantitative study of metazoan meiofauna across the oxygen minimum zone (OMZ) of continental margin in the N-E Arabian Sea in the depth range 500-1965 m was carried out in September-November 2008. Bottom water oxygen and sediment organic carbon showed large variation between stations. The bottom water temperature and salinity was very similar in the area. The fauna was dominated by nematoda followed by harpacticoid copepoda and polychaeta. Maximum meiofaunal density of 164/10 cm² was recorded at St. 1 (500 m) and the lowest density of 25/10 cm² was observed at St. 2 (650 m) which coincided with lowest oxygen concentration. Total abundance of meiofauna was significantly lower than those reported from other areas. The average density was high (65/10 cm²) in OMZ than in non OMZ (52/10 cm²) area. Nematodes were the dominant taxon at every station. The dominance was particularly significant at those stations having very low oxygen. The meiofaunal density was positively correlated with sediment organic carbon while oxygen exhibited a negative correlation. Epibenthic Crustacean groups were more in areas of non OMZ having high oxygen. Vertical distribution revealed consistent reduction in total density and major taxa with increasing depth in sediment. Maximum density was recorded in top 0-2 cm layer. Among environmental parameters the availability of food in the form of sediment carbon appeared to be key factor in controlling meiofauna in study areas. 

Oxygen minimum zone; Meiofauna; Distribution; Arabian Sea